21220102022261 has 2 divisors, whose sum is σ = 21220102022262. Its totient is φ = 21220102022260.

The previous prime is 21220102022233. The next prime is 21220102022281. The reversal of 21220102022261 is 16222020102212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20104184445361 + 1115917576900 = 4483769^2 + 1056370^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220102022261 - 2¹⁴ = 21220102005877 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220102022281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610051011130 + 10610051011131.

It is an arithmetic number, because the mean of its divisors is an integer number (10610051011131).

Almost surely, 2^{21220102022261} is an apocalyptic number.

It is an amenable number.

21220102022261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220102022261 is an equidigital number, since it uses as much as digits as its factorization.

21220102022261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 21220102022261 its reverse (16222020102212), we get a palindrome (37442122124473).

The spelling of 21220102022261 in words is "twenty-one trillion, two hundred twenty billion, one hundred two million, twenty-two thousand, two hundred sixty-one".